1 Rigshospitalet, Copenhagen, Denmark, 2 Statens Serum Institute, Copenhagen, Denmark, 3 University of Copenhagen, Copenhagen, Denmark, 4 Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark, 5 Technical University of Denmark, Copenhagen, Denmark, 6 Massachusetts General Hospital, Boston, MA, United States, 7 Harvard Medical School, Boston, MA, United States <a href=http://sviagrass.monster>does insurance pay for viagra</a> 05 was chosen for all comparisons